The present invention relates to a linear drive comprising a drive member adapted to be reciprocated axially in a housing between two end positions and opposite to which at least one axial side a wall is arranged which is connected with the housing, and means to reduce the impact in the end position, such means having an impact member arranged on the drive member, as a first component, or on the wall, as a second component, and facing the respective other one of such first and second components.
Such a linear drive, which is in the form of a piston and cylinder unit, is disclosed in the U.S. Pat. No. 4,207,807. In this case the drive member is constituted by a piston which is reciprocated by fluid power and in its end positions it strikes a wall of the housing with an impact. In order to reduce the intensity of the impact a washer-like impact member is arranged on the piston or on the opposite housing wall in order to function as a buffer.
Although the drive member and the housing walls of this arrangement are protected against damage directly due to the impacts, the elasticity of the impact member leads to rebound at the end of the stroke so that the drive member does not immediately assume its final or ultimate end position. If an attempt is made to reduce rebound by increasing the pressure acting on the drive member, then when the action of the pressure ceases there is a small return movement of the member, which is just as undesirable and which is due to the elastic deformation of the impact member. In no case is it therefore possible to provide for an even braking or retarding of the drive member at the end of the stroke.